Telephone exchange system



May 12, 1931. c, B, FOWLER 1,804,408

TELEPHONE EXCHANGE SYSTEM Filed Feb 12, 19:50

/NI/EN7'OP C. B. FOWLER ATTOANEY Patented May 12, 1931 UNITED STATESPATENT OFFICE CLARENCE B..FOWLER, QUEENS VILLAGE, NEW YORK, ASSIGNOR T0BELL TELE PHONE LABORATORIES, INCORPORATED, 015 NEW YORK, N. Y.,CORPORATION OF NEW YORK TELEPHONE EXCHANGE SYSTEM Application. filedFebruary 12, i930. Serial No. 427,676.

This invention relates to telephone exchange systems and particularly tosystems in which the service charge is based on the duration ofconversation.

The object of the invention is to simplify the equipment used at thecentral oflice for controlling and operating the service chargingdevices and to otherwise improve systems of the above mentionedcharacter.

It has been proposed in the past to charge a calling subscriber for theservice rendered by means of a meter, located at his substation, whichoperates in response to reversals of currentin the calling line atsuccessive intervals during theperiod the conversational connection isestablished between his line and the called line. versing device isprovided at the central office and is rendered effective either whenconnection is completed to the calling line, as bythe insertion of theanswering plug of a cord circuit, or when the called party answers. a aV c I In the event the call is one for which the calling subscribershould not be charged, it has been proposed to employ a key in theoperators cordcircuit to cancel the charging operation. c

According to the present invention, an improvement is secured over priorsystems by the provision of a cancellationkeywhich is commonto a numberof connecting circuits, such as operators cords, and which inconjunction with the individual talking key prepares a circuit to renderthe registration operation ineffective. I

This invention has been shown in the accompanying drawing in which ithas been incorporated in a cord circuit well known in the art. A callingsubscribers line and a called subscribers line have also been shownequipped with service meters.

A description of a connection through this cord circuit from a callingsubscriber to a called subscriber will now be made; first, in connectionwith a call to be charged for and second, in connection with a freecall. ,When the, operator at cord A inserts plug 2 in jack 3 of acalling subscribers line 4, supervisory relay 5V is operated over acircuit from bat- To this end a current retery, right hand innermake-before-break contacts of relay 6, lower left hand winding ofrepeating coil 7 winding of relay 5, over the calling subscribefis loopback through plug 2 and jack 3 upper left hand winding of repeating coil7 left hand make-beforebreak contacts of relay 6 to ground. An obviouscircuit for lighting lamp lOis also completed by the insertion of plug 2into jack lfhe operation of relay 5 closes an obvious shunt circuit tobattery for supervisory lamp 10 through a common interrupter 11; Thisinterrupter alternately closes and opens this shunt circuit and therebycauses lamp 10 to be intermittently lighted and extinguished forsupervisory purposes as is well known in the art. The operator nowactuates talking key 12 to connect her telephone set across the tip andring conductors ofthe cord and to ascertain the number of the desiredsubscriber. The operation of key 12 also causes the operation of relay13 over a circuit from battery through the no-charge key 145 which iscommon to a plurality of cords, over contacts at key 12, left handwinding of relay 13, left hand windingof relay 15 to ground. Relay 15being marginal does not operate under these circumstances due to the lowvoltage of the battery at the common key 14. Relay 13 in operatingprovides a locking circuit for itself throughits right hand windingunder control ,of relay 5, and disconnects the inter-L rupter 11 fromthe circuit for lamp 10 which is now extinguished due to the shunt pathto battery established at the inner left hand armature and front contactof relay 13.

When the operator receives the number of the wanted subscriber she maycomplete the connection to this subscribers line 16 by inserting plug 17into jack 18. The supervisory lamp 19 is thereby lighted through thesleeve circuit established through plug 17 and jack '18.' The desiredsubscriber may now be. rung in the usual manner through the operation ofa ringing key (not shown). WVhen the subscriber answers the call, thesupervisoryrelay 20 is operated through the subscribers loop in theusual manner. Relay 20 in; operating closes an obvious circuit for thejfoperation of relay 21 to prepare for the connection of the meteroperating battery to the calling subscribers meter 22. This battery isalso used as the talking battery for the calling subscribers line inplace of the normal connected battery at relay 6. Relay 21 in operatingestablishes a connection from ground to one side of the relay 6, throughthe left hand armature and back contact of relay 15. Relay 6 will nowoperate as soon as the circuit for this relay is completed through itswinding and outer right hand armature and back contact, by a commoninterrupter device 23 when this interrupter connects its live segment tobattery. Relay 6 inoperating provides a locking circuit for itselfindependent of the interrupter 28 through its outer right handmake-beforesbreak contacts to battery. This relay also openstheconnections to the normal talking battery supplied for the tip and ringconductors of the cord.

and connects these conductors to the meter and left hand armatures andfront contacts of relay 21 and the armatures ofrelay 3. They polarity ofthis battery is reversed at periodic intervals under control ofinterrupter 30 and relay 31 and will, asis well known in the art, causethe periodic operation of the m'eter'22 in the calling subscribers line.Relay 5 may release momentarily during the reversal of battery and inorderto prevent the signal 10 from being lighted during these periodsrelay 13 is-made slow to release to remain operated.

When the called party disconnects relay 20 is released, causing therelease of relay 21 and therebydisconnects the meter operating andtalking battery from the cord circuit.- Relay 21 in releasing alsocauses the release of relay 6 to reconnect the normal talking battery'tothe calling subscriber s line and when the calling subscriber hangs uphis re ceiver relays 5 and 13 are released, thus removing the shuntforlamp 10 which is now lighted steadily through the sleeve circuit. Incase-the calling party should recall. by

operating his switch hook, relay 5 will be reoperated and cause lamp 10to be alternately lighted and extinguished. The operator would thenanswer this call by the operation of the talking key 12 and cause relay13 to operate to again shunt-lamp 10 as hereinbefore described.

In case the connection to the desired subscriber is one for which nocharge .is to be made, the operator will actuatethe common no-charge key1 1 to cause relay 15 to operate in series with relay 13 when thetalking key 12 has been operated. Relay 15 in operating opens at itsleft hand armature and back contact the circuit for relay 6 and thusprevent its operation when relay 21 is operated at the time the calledsubscriber answers. As relay 6 does not operate the normal talkingbattery can not change to the meter opcrating and talking battery and nocharge can be made on meter 22 during this connection. Relay 15 inoperating provides a looking circuit for itself through its right handwinding under control of the sleeve circuit.

The resistance of this windirrg'replacesthe resistance 30 in the sleevecircuit.

called lines for'conver'sation, meters for'tlre calling lines, a devicefor operating said me; ters during conversation, and means"commentosaidconnect-ing"circuits-for rendering said meter operatingdeviceinefiective mop: erate the meter of anyone ofsaid calling lines.

2. In a telephone system, calling lines, alled lin'esya: plurality'ofconn'e'cting' circuits for connecting calling lines with calledlines, meters for'said calling'lines, means for operating the callingsub'scrib'ers meter during conversation, and a key' common to ap'lurality'of connecting circuits for controlling the operationor'non-operation' of'a'ny of said meters; I V

'3. In" a telephone'system, calling-"lines, called lines, a pluralityofconnecting cir cuits for "interconnecting calling lines with calledlines, a marginal relay in'eaclrcon'nect ing circuit, metersfdrsaidcalling lines, means for operating the callmg subscribers' meterduring conversation, andakey common'to a plurality of connectingcircuits for actuating the marginal relay of anyconnectingcir'cuittorender-the meter of the connected calling. subscribers lineineffective.

4-. In' atelepho'nesystem, calling lines, called lines, a pluralityofconnectingcircuits for connecting calling lines with called lines, akey in each connectingcircuit, meters'for said calling lines, means foroperating" calling line meters while a connection is established, a'key'com'mon to aplural'ity of connecting circuits, and meansresponsiveto the operation of the individual key and the common key for disablingsaid meter operating means.

5. In; a. telephone system, calling. lines, called lines, a pluralityof. connecting circuits for connecting calling lineswithcalled lines, akey in each connecting circuit, metersfor said calling lines,-.means foroperating calling line'meterswhile-a connection is established, amarginal relay in each: connecting circuit, a key common to a pluralityofconnecting circuits, and means responsive to the operation oftheindividual key andthe common key for actuating said marginal relay todisable said meter operating means.

6. In a telephone system, calling lines, called lines, a plurality ofconnecting circuits for connecting calling lines With called lines, akey in each connecting circuit, meters for said calling lines, means foroperating the meter of the calling line While a connection isestablished, a key common to a plurality of connecting circuits, andmeans responsive to the momentary operation of said keys for disablingsaid meter operating means While a connection is established.

7 In a telephone system, calling lines, called lines, a plurality ofconnecting circuits for interconnecting calling lines and called lines,meters for the calling lines, a device for operatlng said meters, andmeans common to said connecting circuits for rendering said meteroperating device ineffective to operate the meter of any one of saidcalling lines.

8. In a telephone system, calling lines, called lines, a plurality ofconnecting circuits for connecting calling lines to called lines, metersfor said calling lines, means for operating the calling subscribersmeter and a key common to a plurality of connecting circuits forcontrolling the operation or nonoperation of any of said meters.

In Witness whereof, I hereunto subscribe my name this 10th day ofFebruary, 1930.

CLARENCE 'B. FOWLER.

